1. Field of the Invention
This invention relates to a profiled cross-section three-dimensional woven fabric, such as a woven fabric having an I-shaped, T-shaped, L-shaped, U-shaped, or otherwise shaped, cross-section, and providing a textile structure suitable for use as a fiber-reinforced composite material such as fiber-reinforced plastic composite material or a woven fabric, three-dimensional structure, such as shown in FIGS. 4 and 7 hereof, for use as an insert core or piece for insertion in a void formed at a portion where laminated webs bend in an I or inverted T-shaped beam fabricated from laminated webs such as shown in U.S. Pat. No. 4,331,723 and Japanese patent laid open application No. 64-75266.
2. Description of Related Art
Japanese Utility Model Application Laid-Open Specification No. Showa 62-79900 shows a three-dimensional woven fabric having a profiled cross-section which comprises intersecting longitudinal, transverse and vertical woven filaments. FIG. 8 of the present application is a cross-sectional view showing an example of such known three-dimensional woven fabric, wherein a number of filaments X are longitudinally disposed in horizontal and vertical parallel planes of differing width to form an I-shape configuration. One transverse filament Y moves upward while transversely reciprocating over a range which varies in conformance with the width of the planes of longitudinal filaments X, until it passes over the upper most plane of longitudinal filaments X and then moves downward while transversely reciprocating in conformance with the planes of the longitudinal filaments X. Such movement is repeated to continuously dispose planes of the transverse horizontal filament Y between vertically adjacent planes of longitudinal filaments X and passes over the outer most ends of the horizontal filament X planes. On the other hand, a vertical filament Z moves longitudinally while vertically reciprocating in a plane perpendicular to the transverse horizontal filament Y over a range corresponding to the height of the various planes of the longitudinal filaments X and the lengths of the planes of the transverse filaments Y, and is continuously disposed between longitudinally planes formed by the Y filaments in adjacent Y filament horizontal planes. The transverse horizontal filaments Y and longitudinal filaments X are tightened together.
In the three-dimensional woven fabric of such Japanese Utility Model Application '900 as shown in FIG. 8A, the vertical filament Z is continuously disposed between longitudinally planes formed by the Y filaments in adjacent Y filament horizontal planes, and transverse and vertical filaments Y and Z are disposed alternately along one longitudinal filament X. Thus, when the transverse filament Y, as shown in FIG. 8, reaches the end of the horizontal filament X plane, and turns to the back of the paper of FIG. 8, i.e., follows the same course, but in the reverse direction, a gap 1 between adjacent horizontal planes of X filaments is left at the opposite sides of the woven three-dimensional fabric. Hence, an unsymmetrical cross-section is formed. Thus, there are formed longitudinal grooves (gaps) 1 at the upper left and lower right end edges of the three-dimensional woven unit where a longitudinal filament X and a loop of transverse filament Y surrounding the same are missing. This raises a problem that, when the structure is impregnated with a synthetic resin to manufacture a fiber-reinforced composite material, the longitudinal gaps 1 form resin reservoirs which cause microcracks.
Further, when the transverse filament Y reaching the upper end, while transversely reciprocating, is turned to the back of the paper, as shown in FIGS. 9 and 10, and returns to the lower side of the longitudinal filaments X, then there are formed transverse grooves (gaps) 2, FIG. 10, in the upper and lower surfaces which, when the structure is impregnated with resin, form resin reservoirs which also causes microcracks.
Conventionally, when the transverse filament Y is turned at transversely opposite ends, it wraps around the longitudinal filament X leaving the longitudinal filament X intermediate above the wrapped filament X free. Thus, as shown in FIG. 11, the region which is narrow, because of the free X filament, is vertically elongated by tension on the transverse filament Y, upsetting the texture of the woven fabric.
In this invention, a three-dimensional profiled cross-section woven fabric is provided, which is easy to weave without forming longitudinal and transverse grooves, such as grooves 1 and 2 in the prior art of FIGS. 8-11. Furthermore, this invention also provides a three-dimensional woven fabric construction for reinforcing portions which are narrow.